1. Field of the Invention
An aspect of the present invention relates to a motion estimation apparatus and method, and more particularly, to a motion estimation apparatus and method that extracts an even motion vector with a high reliability even in a video format conversion technology.
2. Description of the Related Art
In image processing operations, such as frame rate up-conversion (FRC) and interlaced to progressive conversion (IPC), motion estimation between image frames is necessarily performed.
A motion estimation technology estimates a motion vector for motion compensation, and is one of the most core technologies to improve picture quality in various video-processing systems. In general, motion estimation is performed using a block matching algorithm.
The block matching algorithm compares two sequentially inputted frames and fields in the unit of a block, and estimates one motion vector per block. The motion vector is estimated using a motion prediction error value, for example, a sum of absolute difference values (SAD values), and, in a motion compensation process, the motion compensation is performed using the estimated motion vector.
Recently, the motion estimation technology has been widely used in noise reduction operations based on motion compensation, an image compression based on motion compensated prediction, and a video format conversion using motion compensated interpolation.
In the image compression technology based on the motion compensated prediction, a motion estimation technology is mainly used to eliminate temporal redundancy between frames of a moving image.
On the contrary, in the video format conversion technology, the motion estimation technology is used to interpolate and create image data in a spatiotemporal position that has not been stored or transmitted. Therefore, the video format conversion technology requires the motion estimation technology to extract an even motion vector with a high reliability in comparison to the image compression technology.